Martin Gram of Massey's School of Sport and Exercise told RNZ's Jesse Mulligan they had developed a natural protein, made up of a unique amino acid and mineral composition, which was having positive results for the study's participants.

It related to a damaging interaction happening in the blood of those with the disease, he said.

"The elevated glucose levels in the blood is increasing the ... 'reactive oxygen species'."

That could stop insulin working properly, but the protein might help break the circle and act as an antioxidant, he said.

Dr Gram said so far all the participants in the study had noted a decrease in the clinical measure of Type 2 diabetes, HbA1c.

There were currently limited options available for people with Type 2 diabetes, and a natural protein would be a significant development for those with the disease, he said.

If the protein turned out to be efficient, Dr Gram said it could take several years before it became available.

Anyone interested in taking part in the study is asked to contact Massey University in Wellington.